Piezo-electric-crystal apparatus



March 27, 1928. 4 1,663,682

A. CROSSLEY ET AL PIEZO ELECTRIC CRYSTAL APPARATUS Filed March 26. 1926 2 Sheets-Sheet 1 EILE=1 2 March 27, 1928. 1,663,682

A. cRossLEY ET AL,

PIEZO ELECTRIC CRYSTAL APPARATUS Filed March 26. 1926 2 Sheets-Sheet 2 .37 fl E. E- 2/ 7 36 1 -34 l 55 6 12 2.5 k 4 6 J9 J 60 B-/ 36 w a i i J Q V I i *Z i T INVENTORS 14 Z rad Cyvss/e ATTORNEY Patented Mar. 27, 1928.

UNITED STATES PATENTOFFIC.

ALFRED OROSSLEY AND CORRIE F. RUDOLPH, OF WASHINGTON, DISTRICT 01' OOLUE- BIA, ASSIGNORS TO WIRED RADIO, INCL, OF NEW YORK,

DELAWARE.

N. Y., A CORPORATION OI PIEZO-ELECTRIC-CRYSTAL APPARATUS.

Application filed March 26, 1926. I SerlalNo. 97,718.

.Our invention relates" broadly to piezo electric crystal apparatus and more particularly to a multiple holder and-selector for piezo electric crystal devices of different fre- 5 quency characteristics;

The object of our invention is to provlde a multiple crystal holder construction by which piezo electric crystals of different frequency characteristics may be detachably l0 mounted upon a rotatable support and connection established with a selected, one of the piezo crystal devices for frequency control of electrical circuits.

Another object of our invention is to provide a piezo electric crystal apparatus, In

which a rotatable drum is provided for detachably carrying a plurality of piezo electric crystal holders which may be presented to contacts for establishing electrical connection between a selectedpiezo electrical holder and an electrical circuit whose frequency is to be controlled.

Still another object of our invention is to provide a multiple piezo electric crystal 5 holder wherein piezo electric crystals of particular frequency characteristics are mounted within individual casings which may be detachably secured to a rotatable drum member and selectively presented to contacts by which an individual piezo electric crystal may be connected in a frequency control circuit.

A further object of our invention is to provide an apparatus for mounting a'plus rality of piezo electric crystal devices of different frequency characteristics with switching and indicating means for connecting a selected piezo electric crystal in an electrical circuit for the control thereof. Other and further objects of our invention will be understood from the specification hereinafter following by reference to the accompanying drawings in which:

Figure 1 is a front view of the piezo electric crystal apparatus of our invention showing the casing of one of the piezo electric crystal holders in cross-section for illustrating the interior construction thereof, and Fig. 2 is a side elevation of the multiple piezo electric crystal holder partially in cross-section for illustrating the arrangement of the piezo electric devices which are carried by the holder.

In the development of frequency control systems for electron tube signal transmitterswe have found that provision must be made for quick change from one transmiss1on frequency to another which requires that electrical connections between the high frequency oscillator and a plurality of piezo electric crystal devices must be correspondlngly changed to permit a change in the emitted frequency of the transmitter. We have developed a multiple holder for a plurality of piezo electric crystal devices of difi'erentfrequency characteristics by which the crystals may be independently rotected in dust proof casings and electrica connection readily established between a selected piezo electric crystal and the electrical circuit whose frequency is to be controlled. We provide a rotatable carrier upon which a pluralit of piezo electric crystal holders are detac ably mounted. By moving the rotatable carrier a piezo electric crystal of' desired frequency characteristic may be connected in the frequency control circuit at the same time that amechanical indicator advises the operator of the connection of the piezo electric crystal in the circuit. The several piezo electric crystals may be changed at will and the effective frequency thereby quickly changed from one condition to another.

Referring to the drawings in more detail, reference character 1 designates a panel behind which the piezo electric crystal apparatus is mounted. Journal 2 is secured to the panel 1 in which the rotatable shaft 3 is mounted, the shaft projecting through the front of the panel 1 and to the rear thereof. The shaft 3 carries the hub 4 on which is mounted the rotatable drum 5 carrying the piezo electric crystal holders 6.. Each of the piezo electric crystal holders 6 is in the form of a tubular housing with a pair of termi nals 7 and 8 projecting therefrom in the form of plugs which pass through the face of the rotatable drum structure 5 and establish wiping contact with sets of spring contacts 9 and 10 carried by the rear wall of the rotatable drum 5. For each of the wiping contacts 9 we provide a contact point 11 all of which are arranged to establish connection with the spring pressed brush 19 carried by the insulated strip member 17 which is permanently secured to the frame by insulated post 23.and bearing 22 on the 14 into which a spring member 15 supported from block 16 drops during the process of rotation of drum 5. The depressions 14 are directly under the contacting surfaces of each crystal holder and show by presence of a sharp clicking noise when a particular crystal holder has contact established therewlth. This clicking mechanism cooperates with the rotary actuator on the front of panel 1 for indicating definitely when the desired piezo electric crystal is connected in the frequency control circuit. The rotary actuator comprises a knob 31 secured on shaft 3. The knob is fitted with a pointer 32 which cooperates with a scale for definitely representing the frequency of the piezo electric crystal which is connected in the frequency control circuit. The scale consists of a supporting ring member 28 which lies adjacent the front of panel 1 and on which are secured marking indicators 30 behind plate 29 which extends over the disc member 28. A marking indicator showing the frequency of the particular iezo electric crystal inserted in the holder 1n line with.

the marker enables the operator to readily shift from one control frequency to another. The indicator cards may be readily changed when.the piezo electric crystal holders are changed by merely removing the front plate 29 and detaching the old indicator cards 30 and inserting new cards which are secured in position by replacing plate 29. Each of the piezo electric crystal holders 6 comprises a cover portion which screws over an insu+ lated back portion at 39. The plug members 7 and 8 extend into the casing of the holder as indicated at 33 and 34. The screw device 33 supports a resilient arm member 36 forming a guide for a contacting plate 37. The screw device 34 forms a support fora shelf like plate 35. The piezo electric crystal 38 is secured between plates 37 and 35 in a manner in which the piezo electric crystal is free to vibrate mechanically for sustaining electrical oscillations of constant frequency in the electrical circuit with which it is connected by rotation of the drum 5.

The panel structure 1 is apertured at 24 and is provided with a slide 25 which may be moved to aposition to close aperture 24. A hand knob 26 is provided to facilitate the movement of slide 25-into open or closed position. A spring device 27 is arranged on the end of slide 25 for maintaining the slide in close relationship to the rear surface of the panel structure 1. i

It will be observed that the individual crystal holders are symmetrically arranged over the rotatable drum or disc, and as the drum or disc isrotated the crystal holders may be removed or replaced by the operator reaching in through the hand hole .24 and detaching a particular holder and inserting a different holder. The piezo electric crystals in the Various crystal holders are ground to different frequency characteristics so that crystals of different frequency are readily connected or detached from the frequency control circuit, permitting instant shift of the control frequency.

We have described our invention in one of its preferred embodiments, but we desire that it be understood that modifications may be made and that no limitations upon the construction of the apparatus other than are imposed by the scope of the appended claims are intended.

What we claim and desire to secure by Letters Patent of the United States is as follows: a v

1. Piezo electric crystal apparatuscomprising in combination a rotatable carrier, a rotary actuator for impartin movement to said carrier, a plurality of piezo electric, crystal holders removably mounted onsaid carrier, resilient contact members secured to said carrier and electrically connected with individual piezo electric crystal. holders when said holders are inserted upon said carrier, and a pair of contactors for establishing wiping connections with said con tact members when an individual-one of said piezo electric crystal holders is moved to. a selected position.

2. Piezoelectric crystal apparatus comprisin in combination a panel structure, a rotata le shaft journaled in said panel structure, a carrier secured to said shaft immediately behind said panel structure, a plurality of piezo electric crystal holders removably mountedon said carrier, apair of termlnals for each of said piezo electric crystal holders, and a pair of resilient con- 0 tactors arranged adjacent said panel structure for establishing sliding contacts successively with the terminals of each of said piezo electric crystal holders upon rotative movement of said carrier.

3. Piezo electric crystal apparatus comprising in combination a rotatable shaft member, a'disc carried by said shaft member, a plurality of piezo electric crystal holders ren yo ably mounted on one faceof said disc, ar yof said piezo electric crystal holders being provided with contacts resiliently connected with cooperating contacts carried by said disc, and fixed means adjacent to said disc for establishing sliding connection with said cooperating contacts whereby upon rotation of said disc an individual one of said piezo electric crystal holders may be electrically connected with said fixed means.

4. Piezo electric crystal apparatus comprising in combination a rotatable shaft, :1. disc carried by said rotatable shaft, :1 plurality of piezo electric crystal holders arranged to be removably mounted on one side of said disc, terminals for each of said piezo electric crystal holders arranged to project through said disc, electrical contacts carried by the opposite side of said disc for establishing electrical connection with said terminals and fixed means for establishing wiping connection with said contacts for selectivel completing a circuit through an indivi ual one of said piezo electric crystal holders when said disc is rotated to a particular position.

5. Piezo electric crystal apparatus comprisin in combination a frame structure, a. rotata 1e shaft journaled in said frame structure, a carrier secured to said shaft, a plurality of piezo electric crystal holders radially aligned with said shaft and arranged to be detachably secured to said carrier, a piezo electric crystal element arranged in each of said holders with the surfaces of each element extending substantially tangent to a circle drawn around said carrier, individual contacts mounted on said carrier and electrically connected with each of said piezo electric crystal holders, and fixed means for establishing sliding connection with said sets of contacts when said carrier is moved to a selected position by rotation of said shaft.

6. Piezo electric crystal apparatus comprising in combination a frame structure, a rotatable shaft member journaled in said frame structure, a rotatable carrier secured to said shaft member, a plurality of piezo electric crystal holders arranged to be detachably mounted on said rotatable carrier, means for securing access to said rotatable carrier through said frame structure for insorting or removing said piezo electric crys-i tal holders from said rotatable carrier and means for establishing sliding electrical connection with said piezo electric crystal holders for selectively completing electrical connections through a particular piezo electric crystal holder upon rotation of said carrier.

7. Piezo electric crystal apparatus comprising in combination a frame structure, a rotatable shaft journaled in said frame structure. a carrier secured to said shaft, said carrier having means for receiving a plurality of detachable piezo electric crystal holders thereon, sets of spring contacts for each of said piezo electric crystal holders for mechanically securing said holders in position and establishing electrical connection therewith, and means carried by said frame structure for establishing electrical connection with an individual one of said piezo electric crystal holders upon rotation of said carrier.

8. liczo electric crystal apparatus comprising in combination a frame structure, a rotatable shaft journaled in said frame structure, a rotatable carrier secured to said shaft, said rotatable carrier being arranged to receive a plurality of detachable piezo electric crystal holders, sets of contacts for each of said piezo electric crystal holders, and means supported from said frame structure for establishing sliding connection with said contacts upon rotation of said carrier,

said frame structure being arranged to permit the removal and insertion of piezo electric crystal holders from or into said carrier, whereby an electrical circuit may be completed through an individual one of said piezo electric crystal holders.

9. A piezo electric crystal holder comprising a threaded base member, a pair of plug contacts extending outwardly from within said base member, a shelf-like member secured to one of said contacts and a metallic arm secured to the other of said contacts, a contacting plate guided by said metallic arm and a piezo electric crystal mounted between said contacting plate and said shelf-like member for free mechanical vibration.

10. A piezo electric crystal holder comprising in combination a casing, a pair of plug terminals extending outwardly from said casing, a shelf-like plate structure secured in said casing and electrically connected with one of said plug terminals, 2. contacting plate centrally positioned over said shelf like plate structure and a piezo electric crystal positioned between said contacting plate and said shelf like plate structure and arranged for free mechanical vibra tion therebetween.

11. Piezo electric crystal apparatus comprising in combination a frame, a plurality of piezo electric crystal devices carried by said frame, terminals projecting from each of said piezo electric crystal devices and removably insertable into said frame, resilient contact members carried by said frame for detachably engaging the terminals projecting from said piezo electric crystal devices, a set of fixed contacts, and means for moving said frame to successive positions for establishing connections between said fixed contactsand the contact members connecting a selected one of said piezo electric crystal devices.

.12. Piezo electric crystal apparatus comprising in combination a frame, a plurality of piezo electric crystal devices arranged to be detachably mounted in said frame with the surfaces of the piezo electric crystal detacts for establishing electrical connection vices disposed substantially tangent to :1 Oil'- with successive ones of said piezo electric 10 cle drawn around said frame, sets of concrystal devices when said frame is moved tacts supported by said frame and detachwith respect to'saidset of contacts.

ably connected with each of said piezo elec- In testimony whereof we afiix our signatric crystal devices, a set of contacts mount- .tures.- ed adjacent said frame and arranged with ALFRED CROSSLEY.

relation to said first mentioned sets of con- CORRIE F. RUDOLPH. 

